La zona norte de Formentera

Abstract not availabl

The role of 1,25-dihydroxyvitamin D in the inhibition of bone formation induced by skeletal unloading

Skeletal unloading results in osteopenia. To examine the involvement of vitamin D in this process, the rear limbs of growing rats were unloaded and alterations in bone calcium and bone histology were related to changes in serum calcium (Ca), inorganic phosphorus (P sub i), 25-hydroxyvitamin D (25-OH-D), 24,25-dihydroxyvitamin D (24,25(OH)2D and 1,25-dihydroxyvitamin D (1,25(OH)2D. Acute skeletal unloading induced a transitory inhibition of Ca accumulation in unloaded bones. This was accompanied by a transitory rise in serum Ca, a 21% decrease in longitudinal bone growth (P 0.01), a 32% decrease in bone surface lined with osteoblasts (P .05), no change in bone surface lined with osteoclasts and a decrease in circulating (1,25(OH)2D. No significant changes in the serum concentrations of P sub i, 25-OH-D or 24,25(OH)2D were observed. After 2 weeks of unloading, bone Ca stabilized at approximately 70% of control and serum Ca and 1,25(OH)2D returned to control values. Maintenance of a constant serum 1,25(OH)2D concentration by chronic infusion of 1,25(OH)2D (Alza osmotic minipump) throughout the study period did not prevent the bone changes induced by acute unloading. These results suggest that acute skeletal unloading in the growing rat produces a transitory inhibition of bone formation which in turn produces a transitory hypercalcemia

NASA newsletters for the Weber Student Shuttle Involvement Project

Biweekly reports generated for the Weber Student Shuttle Involvement Project (SSIP) are discussed. The reports document the evolution of science, hardware, and logistics for this Shuttle project aboard the eleventh flight of the Space Transportation System (STS-41B), launched from Kennedy Space Center on February 3, 1984, and returned to KSC 8 days later. The reports were intended to keep all members of the team aware of progress in the project and to avoid redundancy and misunderstanding. Since the Weber SSIP was NASA's first orbital rat project, documentation of all actions was essential to assure the success of this complex project. Eleven reports were generated: October 3, 17 and 31; November 14 and 28; and December 12 and 17, 1983; and January 3, 16, and 23; and May 1, 1984. A subject index of the reports is included. The final report of the project is included as an appendix

Antiferromagnetic and Orbital Ordering on a Diamond Lattice Near Quantum Criticality

We present neutron scattering measurements on powder samples of the spinel FeSc2S4 that reveal a previously unobserved magnetic ordering transition occurring at 11.8(2)~K. Magnetic ordering occurs subsequent to a subtle cubic-to-tetragonal structural transition which distorts Fe coordinating sulfur tetrahedra lifting the orbital degeneracy. The application of 1~GPa hydrostatic pressure appears to destabilize this N\'eel state, reducing the transition temperature to 8.6(8)~K and redistributing magnetic spectral weight to higher energies. The relative magnitudes of ordered $\langle m \rangle^2\!=\!3.1(2)$ and fluctuating moments $\langle \delta m \rangle^2\!=\!13(1)$ show that the magnetically ordered ground state of FeSc2S4 is drastically renormalized and in proximity to criticality.Comment: 16 pages, 12 figure

Sleep Disturbances Effect on the Development of Disability Following a Motor Vehicle Collision: A Cohort Study

Purpose: The purpose of this study was to evaluate sleep disturbance and calculate its effect on long-term outcomes for people with whiplash associated disorder (WAD) following a motor vehicle collision (MVC). Methods: A secondary analysis of data for 97 people (females = 72) diagnosed with WAD was collected at 10%. Logistic regression was used to calculate significance and odds ratios (OR) for the variables of age, body mass index (BMI), sex, and sleep disturbance. Results: With logistic regression age and BMI were non-significant factors, however, sex (ꭕ2 = 9.37, p = 0.025; OR = 4.3) and sleep disturbance (ꭕ2 = 17.56, p = 0.002; OR 5.4) were significant factors predicting persistent disability for people with WAD. Conclusion: Sleep disturbance has a moderate effect on the development of persistent WAD while no sleep disturbance is associated with recovery. Assessing and managing sleep disturbance in the health care setting may help to reduce some of the burden of chronic WAD

What Are the Odds? Modern Relevance and Bayes Factor Solutions for MacAlister’s Problem From the 1881 <em>Educational Times</em>

In 1881, Donald MacAlister posed a problem in the Educational Times that remains relevant today. The problem centers on the statistical evidence for the effectiveness of a treatment based on a comparison between two proportions. A brief historical sketch is followed by a discussion of two default Bayesian solutions, one based on a one-sided test between independent rates, and one on a one-sided test between dependent rates. We demonstrate the current-day relevance of MacAlister’s original question with a modern-day example about the effectiveness of an educational program